Sweeper drive and adjustment construction



Nov. 11, 1958 v F. J. MACHOVEC 2,859,461

SWEEPER DRIVE AND ADJUSTMENT conswaucnou v Filed Feb. 12. 1954 4Sheets-Sheet 1 INVENTOR. F250 J M4CA/0V50 Nov. 11, 1958 F. J. MACHOVEC2,859,461

SWEEPER DRIVE AND ADJUSTMENT CONSTRUCTION Filed Feb. 12. 1954 4Sheets-Sheet 2 [N VEN TOR. ["250 J. fld qA/orzc Nov. 11, 1958 F. J.MACHOVEC 2,359,461

SWEEPER DRIVE AND ADJUSTMENT CONSTRUCTION.

Filed Feb. 12. 1954 4 Sheets-Sheet 5 p76. INVENTOR.

Nov. 11, 1958 F. J. MACHOVEC 2,859,461

SWEEPER DRIVE AND- ADJUSTMENT CONSTRUCTION Filed Feb. 12. 1954 4Sheets-Sheet 4 E 6. INVENTOR.

#7250 J. mama 0 Unitecl States Patent SWEEPER DRIVE AND ADJUSTMENTCONSTRUCTION Fred J. Machovec, Pasadena, Calif., assignor, by mesneassignments, to Clarke Sanding Machine Co., a corpo- This inventionrelates to a drive and adjustment construction, and more particularly toa means for driving a power sweeper in forward and reverse directionsand for effecting adjustment of the brushes of the sweeper.

In my co-pending application Serial No. 392,117, filed November 16,1953, for a Sweeper Construction, there is shown and described a novelpower sweeper and suction cleaner of the type adapted to be ridden by anoperator and to clean relatively small or confined areas, such asfactories, sidewalks, etc. The structure there described incorporatesbut a single relatively small gasoline engine which is adapted tooperate not only the suction pump portions of the apparatus, but also toeflect rotation of the various sweeper brushes and to propel theapparatus itself, so that laborious pushing of the sweeper is renderedunnecessary. The present application is directed to the drivingarrangements by which the motor is utilized to effect brush rotation andeffect forward and reverse driving of the sweeper, all under the controlof an operator sitting on the upper forward portion of the apparatus.The application is also directed to the means by which the operator,while remaining in his seat, may effect various adjustments of the maincylindrical sweeper brush and also of the curb brush.

With relation to the drive portions of the sweeper, it will beunderstood that it is desirable that the operator be able to effectforward sweeper movement during the course of a normal sweeperoperation, to eifect rearward movement when it is desired to turn asharp corner or to make a second pass over an area being swept, and toeffect locking of the wheels when the implement is not in use. It isimportant that the controls for the forward and the reverse drives, andfor the brake, be disposed closely adjacent the operators seat. It isalso important that the drive arrangement be relatively simple, flexibleand inexpensive, so that the provision of a drive will not increase thecost of the sweeper unduly.

With relation to the means for adjusting the main and curb brushes, itis pointed out that long continued use of the apparatus causes adecrease in brush diameter making it desirable that the operator efiecta progressive lowering of the brush shaft and thus compensate for thewear. Furthermore, there are many occasions when it is necessary anddesirable to disengage completely the brushes from the ground, forexample when the sweeper is being driven over an area which has alreadybeen swept. According to the present invention, both the fineadjustments, and the complete disengagement of the brushes from theground, may be effected easily by the operator while remaining in hisseat. The drive arrangements, and the brush adjustment arrangements, arenec essarily interdependent in that the brush adjustments could not bemade successfully in the absence of flexible drives which are operativedespite substantial changes in the brush positions.

In view of the above factors characteristic of the field .Of drive andadjustment means for power sweepers of the type indicated, it is anobject of the present invention to provide a simple and effectiveforward and reverse drive controllable by an operator seated on theupper portion of the apparatus.

It is another object of the invention to provide pulley and belt meansby which a driving shaft and a driven shaft may be selectivelyassociated with each other in a manner effecting either forward orreverse rotation of the driven shaft. 7

i It is another object of the invention to provide a brake mechanism fora power sweeper, and which is correlated with the flexible forward andreverse drive of the sweeper in a manner preventing driving of thesweeper in a forward direction while the brake is on. i

A further object is to provide drive means operated by a single motor toeffect rotation of main andcurb brushes,

and also to effect forward and reverse movement of the.

sweeper, and being constructed and arranged to, permit adjustment of themain and curb brushes without impair;

ing or interrupting the drive.

An additional object is to provide means operable from the drivers seatto effect fine adjustment of the main brush position, to disengagecompletely the main brush from the underlying surface, and to disengagethe curb brush from the underlying surface.

These and other objects and advantages of the invention will be morefully set forth in the following specification and claims considered inconnection with the attached drawings to which they relate.

In the drawings: Figure 1 is a top plan view of a sweeper embodyingdrive and adjustment means constructed in accordance with the presentinvention;

Figure 2 is a side elevational view of the sweeper illustrated in Figure1, the drive housing, sprockets and chain being removed to expose themain drive components to view;

Figure 3 is a horizontal sectional view taken centrally of the apparatusand looking downwardly toward the brush and drive components;

Figure 4 is a vertical sectional view taken along the 44 of Figure 3;

Figure 5 is a fragmentary side elevational view,show-.'

ponents, forward and rear sheet metal walls 11 and 12 (Figure 4) mountedon frame 10 and forming a brush chamber 13, and a sheet metal trashreceptacle 14 mounted rearwardly adjacent the brush chamber 13 andcommunicating with it through an opening 16. A'suit-.

able main cylindrical brush 17 is mounted on a horizontal brush shaft 18in brush chamber 13 and is adapted to rotate clockwise, as viewed inFigure 4, to sweep debris and trash through opening 16 andinto thereceptacle 14.

The heavier debris thus thrown into the trash receptacle fallsimmediately to its bottom, but the dust incident to the operation issucked through a nozzle 19 and metal duct 21 (Figures 1 and 2) to asuction pump 22, the latter being mounted above forward brush chamberwall 11 and driven by a gasoline engine 23 located adjacentw thereto. I

The dust drawn through nozzle 19 and duct 21 is discharged from pump 22and through a flexible conduit 24 to a filter apparatus 25 which ismounted on the hinged cover 27 of trash receptacle 14. After a quantityof dust has collected in the filter apparatus 25, the latter is emptiedinto trash receptacle 14 with the emptied dust mixing with the heavierdebris previously deposited in the receptacle due to operation of brush17 The mixed dust and heavier debris may then be emptied from trashreceptacle 14 by pivoting it upwardly and rearwardly on its horizontalpivot axis 28 (Figure 2) until the debris falls through opening 16 andis deposited on the underlying surface at the rear of the sweeper. It isto be noted that pivot axis 28 is located a substantial distance abovetrash receptacle cover 27, and that the actual pivot or. jointconstruction includes a cradle formed of components 29 and 30 of theframe 10.

For a more complete description of the above-mentioned components of thesweeper apparatus, reference is made to my co-pending application citedabove.

According to the present invention, the sweeping apparatus is driven bynovel forward and reverse drive means 32, there being brake means tolock the apparatus against movement when not in use. The inventionfurther contemplates the provision of means 33 (Figure l) for raisingand lowering shaft 18 of main brush 17 both to effect its adjustment andto disengage it completely from the underlying surface, and means 34(Figures 1 and 6) to disengage a curb brush mechanism 36 from theground. The means 33 for adjusting the main brush, and the means 34 fordisengaging curb brush mechanism 36 from the ground, are operabledespite the presence of the drive means 32 and whether or not the drivemeans are operating. The forward and reverse drive means 32, and alsothe various adjustment means 33 and 34, are controlled by an operatorseated on a suitable seat 37 which is disposed above brush chamber 13adjacent suction pump 22 and on the opposite side of the apparatus fromthe main portions of drive 32.

Referring particularly to Figures 2 and 3, it will be noted that thebrush shaft 18 extends at both ends outwardly through the side walls38of brush chamber 13, there being two corresponding pulleys 39 and 40and a sprocket 41 keyed to the end of shaft 18 which is remote from curbbrush mechanism 36. Sprocket 41 is associated with a chain 42 whichconnects it to a relatively small sprocket 43, the latter being keyed atthe outer end of a stub shaft 44 journaled at the forward portion offrame 10. The stub shaft 44 is, in turn, associated with a pulley 46mounting a belt 47 which connects to a second pulley 48 on the shaft ofengine 23. The direction of rotation of engine 23 is such that pulley46, sprockets 41 and 43 and thus shaft .18 are driven clockwise, asviewed in Figures 2 and 4, to effect clockwise rotation of main brush17.

. The present invention is particularly directed to the means forassociating pulleys 39 and 40 on the rotating brush shaft 18 with adrive shaft 49 for the drive wheel 51 of thesweeper, and in such amanner that both forward and reverse rotation of drive wheel 51 may beeffected. Drive shaft 49 is suitably journaled in frame 10, parallel tobrush shaft 18, and is associated by means of a pair of sprockets 52 and53 (Figure 3) and a chain 54 with the axle 56 for drive wheel 51, theaxle being also journaled in frame 10 and centrally of the sweeperbeneath trash receptacle 14.

Proceeding first to a description of the portion of forward and reversemeans 32 which effects selective connection between the brush shaft 18and the drive shaft 49 in a manner resulting in reverse rotation ofdrive wheel 51, a belt 57 is mounted around the outermost pulley 40 ofthe pulleys 39 and 40 on brush shaft 18, and also around a relativelylarge outer pulley 58 which is keyed to the projecting outer end ofdrive shaft 49. Belt 57 also extends forwardly of pulley 40 and around asmall idler pulley 59, the latter being journaled on a generallyvertical lever 61 pivoted at its lower end 62 to a stud 63 (Figure 3) onframe 10. The upper end of lever 61 is pivotally connected to anadjustable link 64 (Figure 2) which in turn is pivoted to the upper endof a generally vertical crank arm 66. Crank arm 66 may be seen, uponreference to Figure 3, to be mounted at the outer end of a horizontallydisposed control rod 67 journaled in frame 10 and extending transverselyof the sweeper, and forwardly of the lower portion of brush chamber wall11, to a point beneath the operators seat 37. At its inner end, remotefrom crank arm 66, the control rod 67 is provided with a foot-crank 68adapted to be pressed by the right foot of the operator.

On pressing of foot-crank 68, the control rod 67 and crank arm 66 arerotated counterclockwise as viewed in Figure 2, operating through link64 to effect counterclockwise rotation of lever 61 on its pivoted lowerend 62. This operates to tighten the belt 57 against the rear portion ofpulley 58 on drive shaft 49, the position of idler 59 being such thatthe lower belt portion is also tightened against the underside of pulley40 on brush shaft 18. Since brush shaft 18 and the pulley 40 thereon aredriven clockwise as previously indicated, the pulley 58 and drive shaft49 are also driven clockwise which effects, through sprockets 52 and 53and chain 54, the clockwise rotation of drive wheel 51 to cause reversemovement of the sweeper. Upon release of foot-crank 68 by the operator,the parts return to their initial positions under the force of a helicaltension spring 76 which is connected between a lug on link 64 and abrake lever 71 to be described subsequently. The belt 57 then becomesloose and its lower portion drops away from the pulley 40, so thatrotation of the latter has no effect in rotating the drive shaft 49 andreverse movement of the sweeper no longer occurs.

It is to be understood that the direction of reverse sweeper movement,and also of forward sweeper movement effected as will be describedsubsequently, are under the control of the operator who grasps a handlebar 73 disposed forwardly of operators seat 37. The handle bar 73 isprovided at the upper end of a vertical steering shaft 74 which issuitably journaled in frame 10 and extends downwardly to a steeringwheel 76, the latter being mounted at its lower end as shown in Figures2 and 4. In addition to the drive wheel 51 and the steering wheel 76,the sweeper apparatus is provided with a caster wheel 77 which ismounted at the forwardportion of frame 10 adjacent pulley 46. Athree-point support is ,thus provided, and which provides effectivebalancedsupport for the apparatus while permitting it to be turned in asmall space.

Referring next to the portion of forward and reverse drive means 32which effects forward movement of the sweeper, a second belt 78 ismounted around inner pulley 39 on brush shaft 18 and also around a pairof relatively small idler pulleys 7 9 and 80. One of the idlers numbered79, is mounted rearwardly of drive shaft 49 on a vertical 7 adjustmentbar 81 which is pivoted at its lower end to the frame 10. The upper endof adjustment bar 81 is formed with a slot 82 which permits, uponloosening of a bolt 83 extended therethrough and into component 30 offrame 10, a slight movement of the bar and the pulley 79 to effect apermanent adjustment of belt tension. To be contrasted with rear idler79, which is only adjusted at infrequent intervals, is the other idlerwhich is mounted forwardly of the brush shaft 18 and a substantialdistance thereabove. Idler 80 is journaled on a relatively horizontaladjustment bar 84 the rear end of which is slidably seated above shaft18 on a bar 86 which forms part of the adjustment means 33 to bedescribed subsequently. At its forward end, bar 84 is connectedpivotally to the upper end of a crank 87 which is keyed to one end of acontrol sleeve 88, the other end of the control sleeve being providedwith a foot crank 89 adapted to be pressed by the left foot of anoperator seated on seat 37. The control sleeve 88 is journaled on asecond control sleeve 91 which in turn is journaled on the control rod67 for the reverse portion of the drive, the arrangement being such thatthe rod 67 and sleeves 88 and 91 of each other.

Referring particularly to Figure 2, it will be noted that belt 78 notonly passes around pulleys 39, 79 and 80, but also passes beneath arelatively small pulley 92 WhlCh is keyed on drive shaft 49 inwardly ofpulley 58. The arrangement of the pulleys, and their relative diameters,are such that the upper component of belt 78 engages the underside ofpulley 92 when the belt is tightened. This occurs when idler pulley 80is shifted forwardly as a result of downward pressing of foot-crank 89,which operates to rotate sleeve 88 and crank arm 87 counterclockwise, asviewed in Figure 2, and shift bar 84 and pulley 80 forwardly. When thepulley 80 is thus in its forward position, the upper and lower portionsof belt 78 are in close engagement with drive pulley 39 so that theclockwise rotation of the pulley 39 will effect counterclockwiserotation of pulley 92 and thus of drive wheel 51 to propel the sweeperforwardly. When the footcrank 89 is released the bar 84 and idler pulley80 are returned to their original rearward positions by a tension spring93 connected between a lug and bar 84 and the upper portion of frame 10.The tension on belt 78 is then lessened so that it drops out of drivingcontact with pulley 92 and also out of operating contact with pulley 39to effect cessation of drive wheel movement. The rearward-shifted orinoperative positions of idler pulley 80, and also of idler 59 for thereverse drive, areunder the control of suitable stops, not shown.

From the above it will be observed that 'a relatively simple means hasbeen provided to effect selective forward and reverse rotation of driveshaft 49 by means of power transmitted brush shaft 18 which operatesconstantly in a single direction. Forward and reverse sweeper movementsmay be effected merely by pressing the foot-cranks 68 and 89, andstopped merely by releasing the same. Because of the mounting of idlers80 and 59 forwardly of the brush shaft 18, the lengths of the connectingmembers 64 and 84 are maintained at a minimum. The provision of idler 79at the rear of the apparatus is important since are movableindependently the brake crank 97 is itself shifted forwardly to cause itpermits adjustment of the operating tension and position of belt 78 in'amatter of minutes, merely by loosening the bolt 83 and pivoting bar 81.

The brake means for stopping thesweeper, after its movement in either aforward or a reverse direction, comprises a brake arm or crank 97 whichis welded to the inner end of sleeve 91 and extends upwardly, as bestshown in Figures 1 and 4, for engagement with a notch 98 formed in thecomponent of frame 10 which supports the drivers seat 37. The movementof brake crank 97 forwardly, after it has been shifted laterally out ofnotch 98, effects counterclockwise rotation of sleeve 91' and thus of anupwardly extending crank 99 mounted at the outer end thereof. Crank 99is-pivotallyconnected at its upper end to a bar 101 extending rearwardlyfor pivotal connection to the upper end of brake lever 71 previouslyindicated. The brake lever 71 is then pivoted forwardly, about its pivotstud 102 which extends outwardly from frame 10 as shown in Figure 3, todisengage a brake shoe 103 from the pulley 58 on drive shaft 49. Thepulley 58 and drive shaft 49 are then freely rotatable until the brakecrank 97 is again shifted rearwardly into its notch 98, which efi'ectsengagement between brake shoe 103 and the pulley 58 to lock drive shaft49, and thus drive wheel 51, against rotation.

It is a feature of the invention that the movement of brake crank 97into notch 98 prevents the foot-crank 89 from being operated to effectforward movement of the sweeper. This is accomplished by providing a'lug 104 (Figure 3) on the inner surface of crank 101, the position ofthe lug being such that it prevents forward movement of crank 87 of theforward drive. The crank 87, and-thus the idler 80, are then preventedfrom being shifted formovement of lug 104 away from crank 87.

Proceeding next to a description of the means 33 for adjusting theheight of brush shaft 18 and main cylindrical brush 17, it will be seenupon reference to Figures 2 and 3 that the brush shaft 18 is journaledat its end portions in bearings 106 disposed in relatively largeapertures or openings 107 in brush chamber side walls 38. Bearings 106may thus move vertically in openings 107, there being extension plates108 mounted radially of bearings 106 to block the passage of air throughopenings 107 regardless of the bearing positions. Each bearing 106 isrigidly mounted, as best illustrated in Figure 2, upon the adjustmentbar 86 previously indicated, the bar 86 being formed of two componentswelded in lapped relationship. The bar 86 at each end of the brush shaftis pivo-tally connected at its forward end 109 to the frame 10, and atits rearward end to a link 111, the latter extending upwardly forpivotal connection to a short crank 112. The crank 112 at each side ofthe apparatus is welded or keyed to a shaft 113 (Figure l) which isjournaled on the upper portion of the sweeper beneath seat 37.

In order to turn the shaft 113 and thus efiect vertical adjustment ofbrush shaft 18 and brush 17, a crank forward portion with a thumb screw117 the lower end of which seats on a horizontal plate 118 welded to araise arm 119. The raise arm 119 is freely pivotable on shaft 113, beingheld against the hub of crank 116 by a compression spring 121 seated ona lug 122 on frame 10. The plate 118 on arm 119 normally seats, underthe effect of gravity, on a stop 123 disposed therebeneath, and thecrank 116 is held a distance above plate 118 which may be varied byturning the thumb screw 117.

In order to decrease the height of main brush 17, for example tocompensate for wear thereon, the operator seated in seat 37 merely turnsthe thumb screw 117 i in a direction decreasing the vertical distancebetween crank 116 and plate 118. Shaft 113 is thus permitted to rotatecounterclockwise a slight amount, as viewed in Figures 2 and 4, andcrank 112 also rotates counterclockwise to effect lowering of link 111.Bar 86 is thus permitted to pivot clockwise to effect lowering ofbearings 106 and brush shaft 18 as desired. Should the operator desireto effect complete disengagement of brush 17 from the underlyingsurface, he merely reaches downwardly with his left hand and lifts theraise arm 119 to effect clockwise movement of crank 116. The varioussuction chamber which is provided forwardly of brush chamber 13 asdescribed in detail in my copending application. After having thus beenswept into the initial suction chamber, the heavier debris remains onthe surface until main brush 17 sweeps it as previously indicated. Anydust in the initial suction chamber is sucked through a hose 124 leadingto the metal duct 21 at the intake of suction pump 22.

The curb brush mechanism 36 comprises a bulls-eye brush 125 mounted on avertical shaft 126 which is journaled in a movable frame 127 formed ofwelded bar components. The frame 127 extends rearwardly from the brush125 and shaft 126 for pivotal connection to an extension of brush shaft18, the arrangement being such that the frame and shaft may pivot orrotate independently of each other. brush 125 comprises a pair ofpulleys 128 and 129 mounted, respectively, on the shafts 18 and 126, anda belt 131 mounted around the pulleys in such a way thatcounterclockwise rotation of shaft 18 (Figure 4) effects The drive forthe aerator.

counterclockwise rotation of the brush 125 as viewed in Figure l. A curbwheel 132 is mounted on frame 127 for engagement with the curb,indicated at 133, and a corresponding wheel 134 is mounted on the frame10 of the sweeper for engagement with curb 133 forwardly of and abovethe wheel 132 as shown in Figure 5.

, The means 34 for disengaging the curb brush mechanism from the groundare best illustrated in Figure 6, and comprise a horizontal plate orbearing surface 136, which is riveted or otherwise secured to the frame10 of the sweeper, and a cam lever 137 which is pivotally connected atits lower end to the curb brush frame 127 as by a bolt 138. The lower orpivoted end of the cam lever is squared, and is formed with a first edge139 which is a relatively short distance from pivot bolt 138, and asecond edge 141 a substantially longer distance therefrom. When the camlever is in a vertical position, the edge 139 is resting on the plate136 and the curbbrush frame 127 is in its lower position effectingengagement of 'brush 125 with the ground or floor. However, when the camlever 137 is pivoted clockwise as vicwed in Figure 6, which may beeffected by the right hand of an operator seated in seat 37, the .edge141 is in engagement with the plate 136, and the bolt 138 and frame 127are elevated from the solid to the dashed line positions shown in Figure6. The frame being thus elevated, the curb brush 125 is lifted olf theground as is desired.

It is to be notedthat the flexible drive between brush shaft 18 andshaft 126 for the curb brush 125 permits raising and lowering of thelatter either while operating or stationary. Furthermore, the flexibleforward and reverse drive means 32 for the sweeper permits the raisingand lowering of the main brush 17 and its shaft 18, due to the operationof adjustment means 33. As the main brush shaft 18 and the brush 17 arethus raised and lowered, the frame 127 for the curb brush mechanism isalso raised and lowered since it is pivoted at its rearward end to theshaft 18. It follows that the various drive and adjustment means areinterdependent since all parts are interconnected and mutuallycooperate.

To summarize briefly the operation of the sweeper apparatus, the engine23 operates both the suction pump 22 and, through belt 47, the pulley46, sprocket 43 and sprocket 41 on brush shaft 18. The brush shaft andits brush 17 are thus rotated clockwise, as viewed in Figure 4, toactuate debris through the opening 16 into trash receptacle 14. The dustincident to the operation is sucked through nozzle 19, duct 21 andsuction pump 22, from which it is discharged through flexible conduit 24tothe filter means 25 which may be emptied periodically into trashreceptacle 14, the latter being pivotable on its axis 23 when it isdesired to empty the trash therein. As the brush shaft 18 rotatesclockwise, the curb brush 125 is alsorotated due to operation of pulleys128 and 129 and belt 131. This effects actuation of debris into theinitial suction chamber, at the front of the apparatus, any initial dustbeing sucked up through hose 124 and into the suction pump.

When it is desired to effect reverse movement of the sweeper, theoperator presses his right foot against footcrank 68 to rotate controlrod 67 and crank arm 66 counterclockwise as viewed in Figure 2, The link64 isthus shifted forwardly to pivot lever 61 counterclockwise and shiftidler pulley 59 forwardly, thus tensioning belt 57 into operatingcontact with pulleys and 58. Pulley 58 is thus driven clockwise, or thesame direction as brush 17, to effect clockwise rotation of drive wheel51, as shown in Figure 4, and cause rearward sweeper movement. When theoperator, seated in seat 37 and steering by means of handle bars 73,desires to effect forward movement of the sweeper he releases foot-crank68 and presses his left foot on foot-crank 89. This effectscounterclockwise rotation of crank 87 (Figure 2) to shift bar 84 andidler pulley 80 forwardly thereby elfecting tensioning of belt 78. Sincethe upper component of belt 78 is in engagement with the underside ofpulley 92 on drive shaft 49, the latter is rotated in the oppositedirection from brush shaft 18, the pulley 39 of which is then indrivingcontact with the belt 78. It follows that the drive wheel 51 is rotatedin the forward direction as desired.

In order to release the brakes of the sweeper, brake crank 97 isdisengaged from its notch 98 (Figure 4) and shifted forwardly orcounterclockwise. This operates, through crank 99, bar 101, and lever 71to disengage brake shoe 103 from pulley 58 and unlock the drive wheel51.

Themain brush shaft 18 may be raised or lowered,

1 a under the control of theoperator seated on seat 37, upon operationof the adjustment means 33 shown in Figure l and described in detailabove, while the curb brush mechanism 36 may be shifted out ofengagement with the underlying surface upon operation of the adjustmentmeans 34 described heretofore.

While the particular apparatus herein shown and described in detail isfully capable of attaining the objects and providing the advantageshereinbefore stated, it is to be understood that it is merelyillustrative of the presently preferred embodiments of the invention andthat no limitations are intended to the details of construction ordesign herein shown other than as definedv in the appended claims.

I claim:

1. In combination, an operator-controlled, self-propelled street sweeperhaving a driving motor, power driven sweeper means, means for effectingselective forward and reverse rotation of a driven shaft relative to adriving shaft coupled to said motor, said means comprising a firstdriving pulley mounted on said driving shaft, a first driven pulleymounted on said driven shaft, a first idler pulley, a first beltencompassing all of said above mentioned pulleys, a carrier for saidfirst idler movable to efiect tensioning of said first belt intooperating engagement with said first driving and driven pulleys andcause rotion thereof in the same direction, a second driving pulleymounted on said driving shaft, a second driven pulley mounted on saiddriven shaft, a second idler pulley, a second belt encompassing saidsecond idler pulley and one of said second driving and driven pulleysand disposed entirely to one side of the other of said driving anddriven pulleys, a carrier for said second idler movable to eifecttensioning of said second belt into operating engagement with saidsecond driving and driven pulleys and cause rotation thereof in oppositedirections, the engagement of said second belt with said other of saidsecond driving and driven pulleys being between the outer belt surfaceand an arcuate section of said other of said second driving and drivenpulleys, means to effect selective movement of said idler carriers andidlers to alternately tension and loosen said first and second belts,and means to drive said sweeper means in the same direction irrespectiveof the direction inwhich said sweeper is being propelled.

2. The invention as claimed in claim 1, in which each of said idlers isdisposed to one side of its associated driving and driven pulleys and ingeneral alignment therewith.

3. The invention as claimed in claim 2, in which said idlers aredisposed on the same side of all of said driving and driven pulleys.

4. The invention as claimed in claim 1, in which'a third idler pulley isadapted to be encompassed by said second belt, said third idler pulleybeing mounted on an idler carrier which is movable to permit adjustmentof said second belt.

5. The invention as claimed in claim 4, in which said second and thirdidlers are disposed on opposite sides of said second driving and drivenpulleys and in general alignment therewith.

6. The invention asclairned-in'claim 1, in which said one of said seconddriving and driven pulleys is said second driving pulley, and said other,of said second driving anddriven pulleys is said second driven pulley.7. A self-propelled pavement sweeper having a main chassis supportingpower driven sweepingmeans, forward andreverse drive means for thesweeper, a motor driven brush shaft, and a drive wheel shaft connectedto the drive wheel of the sweeper, a first driving pulley mounted forrotation 1 said brush shaft, a first driven pulley mounted to rotatesaid drive wheel shaft, a first idler pulley,.a firstbelt encompassingall of the above named pulleys, a carrier for said first idler mountedon said frame andmovable to eifect tensioning of said first belt intooperating engagement with said first driving and driven pulleys andcause rotation thereof in the same direction, a second driving pulleymounted for rotation by said, brush shaft, a second driven pulleymounted to rotate said drive wheel shaft, a second idler pulley, asecond belt encompassing said second driving pulleyand secondidlerpulley and disposed to one side of said second driven pulley, acarrier for said second idler mounted on said frame and movable toeffect tensioning assent 10 a r to effect" tensioning of said secondbelt into operating engagement with said second driving and drivenpulleys and cause rotation of the latter, and means toeifect selecq tivemovement of said idler carriers and idlers to alternately tension andloosen said first and second belts,

13. The power sweeper apparatus as claimed in claim 12, in which a curbbrush mechanism is mounted on said frame and is driven by means of abelt and pulley arrangement associated with said brush shaft, and meansare provided to effect selective engagement and disen gagement of thebrush portion of saidcurb brush mechanism relative to the underlyingsurface.

14. In a power sweeper apparatus, a wheeled frame,

. an engine mounted on said frame, a main sweeper brush of said secondbelt into operating engagement with said second driving and drivenpulleys and cause rotation thereof in opposite directions, theengagement of said second belt with said second driven pulley beingbetween the outer belt surface and an arcuate section of said seconddriven pulley, means to effect selective movement of said idler carriersand idlers to alternately tension and loosen said first and secondbelts, and means to drive said sweeping means in the same directionirrespective of the direction in which said sweeper is being propelled.

8. The invention as claimed in claim 7, in which said idlers are bothdisposed forwardly of said driving and driven pulleys and in generalalignment therewith.

9. The invention as claimed in claim 7, in which the last-named meanscomprises operator-pressed pedals and linkage means associating saidpedals with said idler carriers.

10. The invention as claimed in claim 7, in which a brake shoe isassociated with one of said driven pulleys, and linkage means areprovided to associate said brake shoe and an operator controlled brakemember, whereby said brake shoe may be forced against said one drivenpulley to brake said drive wheel shaft and said drive wheel.

11. The invention as claimed in claim 10, wherein means are provided onsaid linkage means to prevent, when said brake shoe is in brakingengagement with said one driven pulley, the movement of said firstmentioned idler pulley in a direction effecting tensioning of itsassociated belt.

12. In a power sweeper apparatus, a frame, a brush shaft journaledhorizontally in said frame, means to adjust the elevation of said brushshaft, motor means to drive said brush shaft and effect rotation of themain cylindrical brush of the apparatus, a drive wheel shaft journaledin said frame rearwardly of said brush shaft and generally parallelthereto, a drive Wheel associated with said drive wheel shaft fordriving movement in forward and reverse directions depending upon thedirection of rotation of said drive Wheel shaft, a first driving pulleymounted on said brush shaft, a first driven pulley mounted on said drivewheel shaft, a first idler pulley, a first belt encompassing saidpulleys, a carrier for said first idler mounted on said frame andmovable to effect tensioning of said first belt into operatingengagement with said first driving and driven pulleys and cause rotationof the latter, a second driving pulley mounted on said brush shaft, asecond driven pulley mounted on said drive wheel shaft, a second idlerpulley, a second belt encompassing said second idler pulley and one onlyof said second driving and driven pulleys, a carrier for said secondidler mounted on said frame and movable and brush shaft journaled onsaid frame in floating relationship, a drive wheel, flexible drive meansfor operatively connecting said engineto said main brush shaft and tosaid drive wheel, means to adjust the elevation of said main brushshaft, a curbv brush frame. pivotally connected to said main brushshaft, a curb brush having a shaft journaled in said curb brush frame,flexible drive means operatively connecting said main brush shaft tosaid curb brush shaft, and means to pivot said curb brush frame aboutsaid, main brush. shaft to adjust the elevation to said curb brush.-

15. A forward and reverse drive for a sweeper having a frame, a motormounted on said frame, and a cylindrical brush journaled in said framefor operation upon an underlying surface, which comprises first andsecond driving pulleys mounted on said frame and driven by said motor,first and second driven pulleys mounted on said frame and operativelyassociated with the drive wheel of the sweeper, first and second idlersupports movably mounted on said frame, first and second idler pulleysmounted, respectively, on said idler supports, first and second beltsassociated, respectively, with said first and second driving, driven andidler pulleys, and means to move selectively said first idler support totension said first belt into operative relationship with said firstdriving and driven pulleys, and said second idler support to tensionsaid second belt into operative relationship with said second drivingand driven pulleys, the operative relationship being such that thetensioning of said first belt effects forward rotation of said sweeperdrive wheel, that the said tensioning of said second belt effectsreverse rotation of said sweeper drive wheel, and means for driving saidcylindrical brush in one predetermined direction irrespective of thedirection in which said sweeper is propelled.

16. The invention as claimed in claim 15, in which said means to moveselectively said idler supports includes pedals adapted to be pressed bythe operator of the sweeper.

17. A self-propelled surface sweeper comprising a chassis having asingle power-driven supporting wheel means centrally of its rear and apair of non-driven operator-steerable supporting wheels near itsopposite forward corners, a power-driven sweeping brush extendingtransversely of said chassis between said forward and rear supportingwheels including means for driving said sweeping brush in the samedirection irrespective of the direction in which said sweeper is beingpropelled, a corner-cleaning brush supported for rotation about anupright axis, a propelling motor, selectively operable driven meansincluding a plurality of belts and belt pulleys connecting said motorwith said rear supporting wheel, with said transverse brush and withsaid curb brush, and control means for tensioning different ones of saidbelts to propel said sweeper forwardly and rearwardly independently ofthe operation of said transverse brush and of said curb brush.

18. A short-wheel-based, sharp-turning, self-propelled operator-carryingsurface sweeper having a three-wheeled chassis including a power-drivencentrally mounted rear wheel and a pair of steerable small diameterfront wheels all mounted within the confines of said chassis, a p11polling motor mounted laterally of an operatings'tation located betweensaid frontv and rear wheels, means floatingly supporting a transversesweeping brush and a corner-cleaning brush, flexible driving meansinterconmeeting said motor, said brushes and said single rear chassiswheel, said driving means including a plurality of belts andoperator-controlled tensioning means for controlling the tension indifferent ones of said belts between a taut power-transmitting conditionand a lax non-power-transmitting condition.

19. A surface sweeper as defined in claim 18 wherein one of said beltsis effective when tensioned to drive said sweeper forward and wherein asecond belt when tensioned is effective to drive said sweeperrearwardly.

20. A surface sweeper as defined in claim 19 including manuallyreleasable brake means operable from said operating station for brakingsaid single rear wheel against movement in either direction irrespectiveof the tensioned condition of said driving belts. I

21. A surface sweeper as defined in claim 18 including independent meansterminating at said operating station manually adjustable to shift saidtransverse and corner brushes to compensate for wear as well as into andout of surface-cleaning positions.

-References Cited-in thefile of this patent UNITED STATES PATENTSHeacock' May 28, Perry May 19, Warnock Apr. 16, Bonner et a1. Aug. 10,Siddall Nov. 16, Osser Aug. 14, Heifer et al. Jan. 29, Kern Dec. 16,Wilson Mar. 18, Perony Nov. 15, Custer Aug. 18, Wells Apr. 15, PattersonAug. 5, Povinelli June 12, Tom Apr. 8, Machovec Nov. 3, Lison et a1. May18, Lapsley Sept. 28,

FOREIGN PATENTS Great Britain Nov. 16,

